via a comment on susan polgar's blog, i found this interesting item
They may look like worn pieces of an old cardboard chess set, but these little discs contain a prisoner of war escape kit.
When prized open a white bishop from the 'Ajax Chessmen' reveals a tiny compass hidden inside.
And a silk map is believed to still be concealed in the cardboard tube.
Even the innocent handwritten message on the tube which contained the 32 pieces chess pieces is in code.
The chessmen sets were sent to POW camps throughout World War II by MI9 and government department CT6 to help prisoners escape their German captors.
In Colditz kits helped 316 escape attempts which saw 32 men make it all the way home.
Very few of the kits from the early 1940s still exist. This set, which does not contain a board, is being sold at Bonham's auction house in Oxford on December 12.
'These sets are very rare for obvious reasons,' said Robin Lucas, Bonham's resident expert on militaria. 'They are not made of very durable materials so it is amazing that the pieces have survived.
'If there was a board included it could have contained a map, or there might be a silk map still hidden within the tube. But we cannot find that out without X-raying the cardboard or breaking it open.'
It is the first time a cardboard chess set like this has come up for auction in Britain.
Mr Lucas said: 'We know of packs of cards being sold which had different pieces of a map on the back of each card - when assembled they made a complete map.
'There were all different kinds of escape kits smuggled in. Blankets were sent with clothes patterns drawn in invisible ink. These would become clear when soaked in water.
'This meant prisoners could stitch together civilian clothing to wear once they had escaped.
'Monopoly boards and the boards of other games were often used to conceal maps in - when the top was peeled away it would reveal a map underneath.'
POW camps would often have an officer in charge of the escape kit being smuggled in. They would comb parcels to find the games which contained escape aids.
Charles Fraser Smith of government department CT6 and Christopher Clayton Hutton of MI9 where each responsible for designing the methods by which escape kits could be sent to camps.
They never tampered with Red Cross parcels because of concerns the Germans would stop these reaching the prisoners if they did discover items hidden in them.
Instead they sent the games from fictitious London addresses, including buildings which had been destroyed by bombs.
Messages written on the packages and printed labels would carry clues for prisoners.
On this kit the name 'Ajax' alludes to the 'Trojan Horse'. Another sign of the escape aids contained was the phrase 'Patent applied for' and a large full stop point.
Three kisses in the message 'Many happy hours, all my love Dorothy xxx' which was written on the tube, could have indicated the compass was hidden in the third piece inside.
It is not know which camp this game was sent to or how it ended up back in Britain. Bonhams is selling the set for a private seller.
They are estimated to reach up to £500, but are likely to go for much more.